The invention concerns a transport device in a packaging machine having a plurality of circulating endless transport members which each travel via at least one drive wheel, wherein the drive wheels can be adjusted relative to each other in the peripheral direction upon a supporting shaft.
In a packaging machine, in particular in a cartoning machine for folded containers, differing transport members, e.g. in the form of transport chains, are provided for in order to transport the bulk product, i.e. the product to be packaged, the folded containers and, if appropriate, the brochures accompanying the packaging through the machine. Towards this end it is important for the function and the efficiency of the packaging machine that the relative motion of the chains with respect to each other be precisely tuned. This is generally achieved through the precise alignment of chain wheels of the respective chains on a common shaft.
Transport means can also be utilized comprising toothed belts instead of chains and having associated drive wheels in the form of pulleys. These transport means are explicitly included within the purview of the invention.
When the packaging machine is reconfigured to adapt to a different type and amount of bulk product and associated folded container, the drive wheels must be newly aligned with respect to each other on the common shaft. Towards this end one has, in the past, held at least one drive wheel on the shaft in a detachable fashion using a screw clamp arrangement so that, after loosening of the clamping screw, a manual adjustment of the drive wheel in the peripheral direction, i.e. a rotation of the drive wheel is possible. After the drive wheel has been adjusted to the desired rotational position, it is once more fixed to the shaft by tightening the clamping screw. This procedure is time consuming and relatively imprecise.
In a conventional arrangement disclosed in DE 43 14 632 C2, each adjustable chain wheel (disposed on a central shaft in a freely rotating fashion) has its own coaxial toothed wheel in engagement with a drive toothed wheel seating on a secondary shaft disposed parallel to the central shaft, wherein the central shaft and the secondary shaft can be synchronously driven by means of a linkage. The linkage driving both shafts comprises a drive wheel seating in a rotationally secure fashion on the central shaft as well as a drive wheel seated for rotation on the secondary shaft and having a pneumatic clutch. When the clutch is activated, a coupling bushing is also activated which fixes the secondary shaft with the drive wheel borne thereon in a rotationally secure fashion. In order to adjust the chain wheels, the secondary shaft can be decoupled from the drive using the clutch, to permit relative motion of the chain wheels via the drive. The amount of constructive effort required by this device is however quite extensive. In particular, the secondary shaft and additional drive require a substantial amount of space within the packaging machine.
It is the underlying purpose of the invention to create a transport device in a packaging machine of the above mentioned kind with which the relative adjustment of the drive wheels is facilitated in a simple and precise fashion and requiring only a small amount of space.